Green tea: Side Effects, Interactions and Who Should Avoid It

Most herbal articles talk up the benefits and bury the cautions at the bottom. This one starts with them, because Green tea deserves a straight answer about who should not take it.

What the research says about safety

On safety: no safety concerns have been reported for green tea consumed as a beverage by adults. However, green tea does contain caffeine. Side effects of green tea extract supplements include nausea, constipation, abdominal discomfort, and increased blood pressure. Manufacturers and distributors of supplements are responsible for evaluating the safety and labeling of their products before marketing to ensure that they meet all regulatory requirements.

The traditional warnings

Chinese medicine has its own caution list, based on the herb's nature rather than trials: tannins block iron and many medicines, so separate tea from supplements by an hour; strong late tea disturbs sleep. A practitioner checks your pattern before prescribing precisely for this reason.

Common-sense rules

Keep to food-level amounts unless a practitioner says otherwise, take breaks rather than running any herb continuously for months, and stop at the first sign that something disagrees with you. If you are pregnant, breastfeeding, on prescription medication or managing a chronic condition, talk to a professional before starting.

Consistency beats dose. A modest amount taken regularly usually does more than a heroic amount taken twice.